The present invention relates to formation of a range of fluid exothermic compositions and of having these enclosed in what are known generally as pouches by such a transfer, which now enable high-speed manufacture of ultra-thin filled pouches, the filled composition being uniformly distributable, and each of such exothermic pouches being thin, soft and flexible and excelled in touch in use because of the fluid feature of, e.g., the transferred exothermic composition which can be packed in a mating bag partly or entirely fixed thereto, and the invention also relates thereto.